Method and apparatus for preventing offset in printing



ug. l5, 1933. 'r- E; KNQWLTON 1,922,372

METHOD AND APPARATUS FOR PREVENTING OFFSET IN PRINTINGl Filed Aug. 30. 1930 f UNI- TED STATES. PATENT OFFICE i 1,922,37a s. i Mtrnon ANDRAPMRTS".FQItREVENT-` c s s, ING` OFFSET IN PRINTING" Theodore E. Knowlton, New York,V `N. Y. Appt-[cation August 3o, 1930; serial 10,478,840 20 Clairns. (Cl. lOl-422) 3 This` invention relatesmto a method and appaby feeding saine in contact with a series of printratusfor printingwherebyr both sides of a blank ing rolls disposed to prntf'rst on one side and ig s sheet maybe printed with characters', `Inarks, then on the reverse side ofV the blank. In the colors or Vsymbols in clear,` distinct outlines Withillustrated constructions, aseries ofprinting cyl- 5` out any smearing or blurring resulting on the inders are horizontally disposed with roll2y ar- 6i) printed j` sheet. It pertains .particularly` to the ranged to print the sheet on the bottom side and impression or tympan cylinder orcyl'indersfaced the printing cylinder 3 arranged to printfthe `vvithafnovel and improved printingblanket, or sheet onthe reverseside. Roll 4 is a convenan off-set meansassociated with a printing aptional tympan cylinder cooperating'` with the l paratus. t Y printing cylinders2 to support the blank while 65 The invention consists inthe novel methods, vtheprinted matter isbeing imparted thereto, `and i combinations and arrangements hereinafter denumeral 6" typies an inking device for the printscribed for carrying out thehabovestated object ing cylinders. While 1 `have shown the printing and such other objects as willherein-after appear. cylinders -to be horizontally disposed, it Will be l5 `This'` invention may be understood readily by understoodthat this is merely one illustration. 70 reference to exemplifications of cylinder print- They may be vertically disposed or arrangedin ing presses described in the following specica- Vany other `desired manner to print alternately on tion,l in which saine is usedalthougn it is not ilirst one sideY and then on the other side of the to be understoodthat the,inventionislimited to blank Lwithout departing from the spirit of the any particular printing apparatus.` `It` may be invention. Y .s s s 's employed with hat bed presses` as well as with Printing cylinder 3 of the second series of printl the cylinder type. VIn such" exemplii'cations, a ingycylinders is similar to printing cylinder 2, and i 1 blank to be printed, for example paper, is fed is likewise provided with an inking device rep-` `throughvany conventional type oi printing apresented at 7s. s However,afterV the blank has been v i paratus having one or both of the tympan cylinprinted on one; side andis thenprinted on the 80 ders providedwith aqprinting blanketg-cornprisreverseiside before 4the ink has dried, care must `ing a;thinysmoothesurfaced, flexible structure,` be taken to'- avoid smearing or blurring onthe v approximating: in Vhardness the character, of printed side, 1t has `beencustomary heretofore l metal. "Composition material or lesserfstabil-ity torunan offset sheet of ink-repellentniaterial than metal will not endure for any length of over the vtympan cylinder .5 to avoid destruction 85 time theseverje Wearand Vtearto which ityissublof or ivzlijukrytv)` the printed side, but this has ymet jected, `and replacements areirequent. jMy in-jl withonly partial success. Eventhough the o ffvention aims to provide aprinting blankethavL Asetbe of especial grade `of Amaterial, it willnot ing the hardness and'stability ofmetalpyetsuf- Prevent blurring O ftlie outlines or avoid picking ggf ciently iiexible and elastic to `yield under the up the ink fronthe sheetwhile in contact with: 90 t compressing force of the' impression cylinderf the blank, -Becanseit does take on inkfrom the :Illustration has been made vonly of 1 that part printed sheeththe offsetsheet is unt for conofthe-printing fi'prmratusV vwhich is" :utilizedto tiriuous use withoutimminent danger of V,injury carry Ithe present inventionlinto effect'. toutheprited mattenontl'ieblank` When the Y M40 Inztnedrawing i 0fisetsheet'is Constructed ot rubberizedvfabric -95 Fig 1 is a view in centralverticalsectional ele- `orthe like, it` sooncracks-and peels, s s .vation of thatpart of a' printing apparatus emlI` have discovered that a durable oiset sheet bodying myfinvention; i f `may bei constructed o f a smo oth, thin` flexible `vFig. 2 isa` similarview ofanother modiiiea'-` material approximating in, hardness the char- 2 tion; l s

rias is'1asimi1arview of Stili another modiherently elastiand compressipleas wenas nexication; and] i c y l ble, or itmay beacomposite structure, comprising `1 Fig. 4 represents, on `a larger' saaie, theperipha hard; flexible Surfacing layer'and a spportins eralz structure of `the second series` of` printing layer Qflaslii and C OmpreSSible materialof Vdifl andtympan cylinders". i 1 l feren'characteh Y 105 Referring tothe drawing, 1 designates a blank A iiexiblemetal issuitablenfor the smooth, thin sheet which is fed from reel A through a print- "surfacing layer and is typified by metal sheet 8 ing apparatus and then cut into sheets, wound applied directly to the face of the tympan cylin- `upon reel B, orotherwise disposed of afterit has der over a` conventional `printing blanket or any N been printed.` Thefsheetis printed on both sides elastic sub-structure 9. It may be tightly 11110 fics ac ter of nietah This maybe asingle sheet in- 1:00

clamped over the face of the tympan cylinder in any well known manner (Fig. 1) or may be in the form of endless belt 12 (Fig. 2) circumvolved over tympan cylinder 5 and one or more idlers 13 and 14. In the modication of Fig. 3 the flexible metal sheet is in the form of a strip 15 adapted to be transferred from feed roll 16 over tympan roll 5 to a winding'roll 17, after which it may be used repeatedly.

The invention is especially adapted for use in the printing of newspapers as Well as for better quality Work. The character of the metal sheet or the like is such that it may be readily cleaned Without being softened or otherwise affected by cleaning materials.

Obviously the present invention is not restricted to the particular embodiments herein shown and described, neither is it necessary that all features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations.

I clairng' 1.-A method -of preventing offset in printing characterized by printing a blank sheet upon one face, supporting the sheet on a smooth-surfaced, non-absorbent metal layer, and then printing the sheet on the' reverse side.

2. A method of preventing offsetin printing characterized by printing a blank sheet` upon one face, supporting the sheet on a relatively hard, smooth-surfaced, non-absorbent unitary flexible layer, and printing the sheet on` the reverse side while same is supported on the relatively hard, 'flexible layer.

3. A method oi concomitantly printing a blank sheet on opposite faces comprising feeding a blank sheet in contact with a printing element, traversing a relatively hard, smooth-surfaced, non-absorbent unitary exible layer in contact with the blank sheet, and immediately feeding the sheet in contact with a printing element While supported on said support to print the reverse side of the sheet. 4. A method ofconcomitantly printing a blank sheet on opposite faces comprising feeding one face of a sheet in contact with a'printing roll, traversing a smooth-surfaced, non-absorbent unitary flexible, relatively hard support with the sheet, and print-ing the reverse face of the sheet while on said relatively hard, iieXible support.' Y 5. A-method of` preventing offset in printing a blank sheet on opposite faces comprising printing vone face `of the sheet, supporting the sheet on the printed side over arelatively hard,"l smoothsurfaced, non-absorbent unitary'surface, and simultaneously printing the reverse face. l

- 6. The method of preventing oflsetin printing a blank sheet on opposite faces comprising first printing one face of the sheet, traversing the sheet in contact With'a smooth-surfaced', ink-'repellent exible metal layer, and simultaneously printing the'revers'e face.

7. The method of successively printin'gopposite faces of a continuously traversing sheet and supporting said sheet on a smooth-surfaced inkrepellent flexible'metal layer to receive the subsequent print.

8. A method of preventing offset in prnting vcharacterised by printing a blank upon one face, supporting said blank on a platen with the printedside in contact with a thin, smooth-surfaced, ink-repellent ilexible metal layer, and printing the reverse side While in contact with the metal layer.

9. Printing apparatus comprising a series of printing rolls disposed to print on opposite faces of a sheet, tympan rolls cooperating with the printing rolls, and a relatively smooth-surfaced, ink-repellent hard, flexible layer homogeneous in character cooperating with the print roll which prints the reverse face of the sheet.

10. Printing apparatus comprising a series of printing elements disposed to print alternately on opposite faces of a sheet, supporting means cooperating With the'printing elements, and a re1- atively smooth-surfaced, ink-repellent hard, ilexible layer homogeneous in character associated with the subsequent supporting means to prevent dispersion of the ink on the initially printed face.

ll. In a printing apparatus of the character described, means for successively printing on opposite sides of a continuously traversing sheet, and a relatively hard, smooth-surfaced non-absorbent layer of homogeneous character for supporting the sheet subsequent to the initial printing.

12. In a printing apparatus of the character described, a printing and tympan roll for printing one face of a sheet, a printing and tympan roll disposed to print the reverse side of the sheet, and a relatively hard, smooth-surfaced non-absorbent layer of homogeneous character traversing with the second tympan roll to contact with the printed face of the sheet.

13. 1n a printing apparatus of the character described, means for printing one face of a traversing. sheet, means for printing the reverse face of the sheet, and a smooth-surfaced dry flexible metal faced tympan roll cooperating with the second printing means.

14. A printing apparatus of the character described comprising a printing device, a platen associated with the printing device, and means faced with a dry smooth-surfaced flexible metal layer cooperating with the platen to support a printed blank.

15. A printing apparatus comprising a printing device, a platen associated with the printing device,l and a facing for the platen including a smooth-surfaced, ink-repellent exible metal layer to support a printed blank.

15. A platen mean-s for a printing apparatus having a smooth-surfaced ink-repellent layer of homogeneous character on which a printed sheet is adapted to be supported.

17;'Printing apparatus comprising a series of printing rolls disposed to print on opposite faces Y ink-repellent flexible metal.

THODORE E. kKNOWLTON. 

